21964446 has 60 divisors (see below), whose sum is σ = 57272688. Its totient is φ = 6273288.

The previous prime is 21964429. The next prime is 21964451. The reversal of 21964446 is 64446912.

21964446 is a `hidden beast` number, since 2 + 1 + 9 + 644 + 4 + 6 = 666.

It is a self number, because there is not a number n which added to its sum of digits gives 21964446.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 29 ways as a sum of consecutive naturals, for example, 6555 + ... + 9321.

Almost surely, 2^21964446 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21964446, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28636344).

21964446 is an abundant number, since it is smaller than the sum of its proper divisors (35308242).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21964446 is a wasteful number, since it uses less digits than its factorization.

21964446 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2795 (or 2779 counting only the distinct ones).

The product of its digits is 41472, while the sum is 36.

The square root of 21964446 is about 4686.6241581761. The cubic root of 21964446 is about 280.0529066692.

The spelling of 21964446 in words is "twenty-one million, nine hundred sixty-four thousand, four hundred forty-six".